A communication disorder is a disease or condition that partially or totally prevents human communication. The defect can be in producing, receiving or understanding the communication.
Examples of communication disorders:
autism -- a developmental defect that affects understanding of emotional communication
aphasia -- loss of the ability to produce or comprehend language
... 3.90% African American, 0.20% Native American, 2.13% Asian, 0.05% Pacific Islander, 3.49% from other races, and 1.95% from two or more races. 11.66% of the population ...